Care Tips: Fall

Care Tips: Fall

It will be frosting soon. Have you prepared your indoor tree area for that fateful night when you do the bonsai shuffle? Are you going to take them in and out until it is constantly too cold to be outside? I don’t, but many do. I have an unheated greenhouse so I stage the indoor trees there until it gets pretty cold. I try to gauge the temperature dips at night to judge that day that they need to come indoors. In the interim, I spray them to get rid of unwelcome passengers. It seems to hold off the first outbreak of white fly by at least a month.

Outdoor with lower temperatures, watering becomes more of a look and see, rather than, just water – it was hot. Cool weather coupled with cloudy days can let you skip water most plants a few days out of the week. Why “most” and not all, you ask? Because pots are different sizes and trees use water at different rates, but most importantly, pot bound trees really don’t have any soil left in their pots to hold water. You can see the water having trouble soaking in, or just running off. Mark these to be repotted first in the spring. If they are really bad, you may want to stick them in the ground (without their pot) soon. If you don’t they may dry out and die. At the very least they will probably break their posts during the winter.

If you can, sort your trees into their known or suspected climatic zones, those that aren’t nearly as hardy will need more protection. These include some Chinese elms and Japanese maples. You may hear some members say they put them in their garage for the winter, mine is too warm. As you stage your indoor trees to bring them inside, put them in a shadier area because they will soon need to get used to a lower amount of light. This reduction may reduce the leaf drop you will get when you bring them in.

I unwire trees that have had their wire on for more than three months, simply because with my collection, in the spring when the sap begins to flow, wire will quickly cut in. Also this is a good time to wire some trees that you didn’t have time for in the spring. While the wire won’t do much due to the slow or non-existent rate of growth in the winter you can leave the wire on a bit longer than you can when you wire in the spring. For the same reasons, you should have stopped or scaled back nitrogen fertilizers on your outdoor trees (new growth may die because it hasn’t had a chance to harden before winter, and indoor trees need a rest to, so slow down on them – or wait until you bring them in and they have a chance to adjust. Mine usually stop growing for awhile, but then you will notice new growth due to your warmer house conditions.

As you handle your outdoor trees to get them ready to store in a non-windy, non-sunny location until you are sure that it’s safe to bring them out, you can do some pruning or wiring. You may discover some trees have really branched out and you missed pinching or pruning them. Do it now so the side buds get the strength of those spring growth hormones the trees put into the first flush of growth. Lay in some mulch to protect the root balls from freezing too hard. And if you have trees that give a great fall color show – move them to center stage!

~ Ken Schultz

The Columbus Bonsai Society receives meeting space and other support and assistance from the "Franklin Park Conservatory and Botanical Garden" and Oakland Nurseries